Until the early 1990s, it was customary for EMS systems to be provided with proprietary hardware and operating systems. During that time, companies like Harris Controls (now GE), Hitachi, Cebyc, Control Data Corporation, Siemens, and Toshiba produced their own distinct hardware platforms. EMS providers who did not produce their own hardware frequently depended on products designed by Digital Equipment, Gould Electronics, and MODCOMP. One particular favored option among certain EMS suppliers was the VAX 11/780 manufactured by Digital Equipment. In the present, EMS systems depend on a model-based approach. Previously, traditional planning models and EMS models were maintained as separate entities and rarely aligned with each other. The utilization of EMS software enables planners and operators to utilize a shared model, thereby minimizing discrepancies between the two parties and reducing model maintenance efforts by 50%. Additionally, the presence of a unified user interface facilitates seamless information transfer from planning to operations.
An energy management system based on rules prioritizes the development and execution of the logic that governs the distribution of energy among interconnected Distributed Energy Resources (DERS). This system depends on predetermined guidelines and established rules to make immediate determinations regarding the allocation of energy. By implementing a rule-based approach, operational stability is guaranteed, which makes it applicable in situations where simple decision parameters can effectively achieve energy management.
With the decline in cost-effectiveness of proprietary systems, EMS suppliers started offering solutions that relied on industry standard hardware platforms, such as those provided by Digital Equipment (later Compaq and then HP), IBM, and Sun. During that period, the prevailing operating systems were either DEC OpenVMS or Unix. By the year 2004, different suppliers of EMS such as Alstom, ABB, and OSI had initiated the provision of solutions based on the Windows operating system. Subsequently, by 2006, customers were provided with the option of selecting systems based on UNIX, Linux, or Windows. Several suppliers, such as ETAP, NARI, PSI-CNI, and Siemens, still provide solutions based on UNIX. It has become a prevalent practice for suppliers to incorporate UNIX-based solutions on either the Sun Solaris or IBM platform. More modern EMS systems that utilize blade servers take up significantly less space compared to previous versions. As an illustration, a blade rack containing 20 servers occupies approximately the same amount of space as a single MicroVAX server did in the past.
